About FLEX I/O Analog Calibration
The FLEX I/O analog modules are calibrated for 150 Hz, 300 Hz and 600 Hz prior to shipment. As time passes, the electrical specifications of various electronic components of your analog module drift. In order to obtain the best possible accuracy in measurements made by your analog input module and signals generated by your analog output module, it is necessary to recalibrate from time to time. Recalibrating once every six months is an appropriate interval for most applications.
When you find it necessary to re-calibrate, you must do it with the module in a FLEX I/O system. The module must communicate with the controller and the
Logix Designer
application.
TIP:
Before you calibrate a module, you must complete its configuration and Apply or Download (depending on the module) the settings and then inhibit the module’s connection by checking the Inhibit checkbox from the Connection tab. Once you complete these steps, you can start calibration.
There are two general functions in the calibration process:
- Offset
- Gain
The
Logix Designer
application calibration screens guide you through the entire process. You calibrate input channels first and output channels second. Refer to the equipment requirements below for a list of the necessary calibration equipment for input channels and output channels.
IMPORTANT:
Calibration of a FLEX I/O analog module accepts any data you provide. You must provide accurate signals for an input calibration and accurate measurements for an output calibration. Providing accurate signals enables your analog module to operate at its rated accuracy.
Calibration proceeds without reporting an error whether you attach the correct signal or not attach a signal at all. It is possible to completely uncalibrate the module by not following the on-screen directions. The software does not report that the module is uncalibrated.
- For input channels: Attach a reference source (voltage or current) and the module reads the value.
In order to calibrate the module, you need the following equipment:
Equipment | Description | Model/Type |
Precision Voltage/Current Source | 0 – 10.25V, 10mV resolution or better 0 –21mA, 100nA or better | HP3245A or equivalent |
- For output channels: Measure the voltage or current and enter the value into a field on the screen. The software generates calibration correction values, based on these measurements, and stores them in the module.
In order to calibrate the module, you need the following equipment:
Equipment | Description | Model/Type |
Precision Voltage/Current Meter | 0 – 10.5V, 10mV resolution or better 0 –22mA, 100nA or better | Datron, Wavetek or equivalent |
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